1. Field of the Invention
This invention relates generally to rectal specula and, more particularly, to a speculum for use with a colonic lavage machine.
2. Description of the Prior Art
Devices are known for lavaging the lower intestinal tract of patients suffering from colitis and similar ailments. Examples of such devices can be found in U.S. Pat. Nos. 2,826,197, 3,771,522 and 4,190,059. These devices commonly employ a speculum for directing treating fluids into the patient's colon and subsequently allowing the discharge of fluidized waste matter.
Typically, the rectal specula used with the above devices are formed of a pair of concentric tubes; and inlet tube carries water into the patient's rectum and colon and a discharge tube allows fluidized waste matter to flow out. In order to facilitate insertion of the speculum into the patient's rectal canal, to decrease the patient's discomfort and possible pain and to avoid possible injury to the patient's intestinal tract, the speculum is usually used in combination with an obturator. An obturator typically is an elongated rod having a tapered, cone like portion at one end and a handle portion at the opposite end. The obturator may be inserted through the hollow interior of the speculum from the proximal end to extend the cone like portion from the distal end. The cone like portion facilitates insertion of the speculum. Once the speculum is in place, the obturator is removed by gripping the handle portion and withdrawing it from the speculum.
Conventional specula suffer from a number of drawbacks. In particular, specula having a concentric tube structure are difficult and expensive to manufacture and they are inconvenient to clean and maintain. Furthermore, the process of attaching a discharge hose or conduit to the outlet end of a speculum after removal of an obturator can be painful since the inlet end of the speculum is free to rock or slip in the patient's rectum while the discharge conduit is being attached.
In an attempt to solve the first of these drawbacks, a speculum has been introduced which does away with the conventional concentric tube structure; it is illustrated in U.S. Design Pat. No. D228,204. The Holt speculum includes an unobstructed main tube with a distal end adapted for insertion into a patient's rectum and a proximal end adapted for connection to a waste removal hose; an intersecting inlet tube connectible to a source of water injects water into the main tube. The inlet tube is considerably smaller in diameter than the main tube and is disposed at an acute angle at the discharge end of the main tube. This angle produces a slight fluid flow in the direction of the patient's colon when the lavaging machine is in operation. Once the Holt speculum has been inserted and an associated obturator removed, a waste removal hose must be connected to the proximal end of the tube. Water or other treating fluid flows through the inlet tube to fill up the main tube and waste removal hose until a sufficient back pressure exists to direct the treating fluid into the intestine. When the fluid pressure in the intestine is equal to or greater than the pressure in the main tube and the waste discharge tube, the treating fluid and fluidized waste matter is discharged through the speculum. A drawback of the Holt structure is that the waste matter to be discharged must flow counter to the direction of the fluid flow from the inlet. The resulting pressure on the patient's intestine is relieved more slowly and less effectively than with a speculum in which the waste matter to be discharged does not have to overcome a counter flow. Accordingly, the patient suffers greater pain and discomfort than is necessary. A need therefore exists for a new and improved rectal speculum which overcomes some of the problems and shortcomings of the prior art.